Houston, Texas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

049
FXUS64 KHGX 201835
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
135 PM CDT Sun Jul 20 2025

...New KEY MESSAGES, DISCUSSION, MARINE...

.KEY MESSAGES...
Issued at 132 PM CDT Sun Jul 20 2025

- Another hot and mostly dry day across the region. While the main
topic is heat, some isolated showers and thunderstorms will be
possible this afternoon.

- A gradual warming trend will lead to hotter conditions by mid-
week, with heat index values approaching or exceeding advisory
criteria.

- Whether or not an advisory is issued, those individuals who are
vulnerable to heat, or will need to exert themselves strenuously
outdoors should have a plan to stay ahead of heat illness this  week.

- Later in the week, a surge of tropical moisture will increase
  rain and storm chances.


&&

.DISCUSSION...
Issued at 132 PM CDT Sun Jul 20 2025

The influence of upper-level ridging will maintain hot and largely
dry conditions across Southeast TX this afternoon and evening.
However, a combination of subtle upper-level forcing, surface
convergence (due to seabreeze), diurnal heating, and low-level
instability have been enough energy to support the development of a
few showers and thunderstorms this afternoon. These showers/storms
are isolated and/or short-lived. Additionally, a passing low-level
jet across central TX could lead to wind gusts from 20 to 35 knots
this afternoon. Rain/storms should taper off late this
afternoon/early evening.

Ridging aloft will remain strong over the region while sfc high
pressure centered over the Gulf shifts westward into TX. This
pattern will usher in a gradual warming trend and relatively drier
conditions for much of the period. 850 mb temperatures, a good
indicator of lower atmospheric heat, are projected to be in the 20
to 24 degC throughout most of the week. This translates to daytime
high temperatures climbing into the mid to upper 90s by mid-week.
Hot weather naturally means heat values in the triple digits. While
current model guidance suggests a drier airmass in the afternoons,
which could keep heat indices near or just below advisory levels, we
will continue to closely monitor this trend as temperatures climb.
Regardless of whether heat advisories are issued, it will be hot. It
is always encouraged to practice heat safety by staying hydrated,
limiting outdoor exposure during peak heating hours and wearing
light-weight colored clothes.

As we head towards the end of the week, upper ridging is forecast to
weaken, paving the way for less stable conditions and increasing
rain and storm chances. A surge of tropical moisture, associated
with a coastal trough/frontal boundary, is expected to arrive into
the region sometime between Thursday and the weekend. Latest model
guidance continues to indicate weak to no development with this
disturbance. However, the consistent trend is for increasing rain
and storm chances form east to west, particularly on Friday and
Saturday, as this surge of moisture moves in.

JM

&&

.AVIATION...
(12Z TAF Issuance)
Issued at 620 AM CDT Sun Jul 20 2025

A few isolated showers around GLS and lingering patchy fog at CXO
this morning, but otherwise dry and VFR conditions will prevail
throughout the day across the region. Southerly to southeasterly
winds will be a bit gusty at times during the afternoon hours.
Expect sustained winds around 10-15 kt with occasional gusts in
the 15-20 kt range through sunset. Could see a repeat of patchy
fog and/or MVFR ceilings developing at the northern terminals on
early Monday morning.

Batiste

&&

.MARINE...
Issued at 132 PM CDT Sun Jul 20 2025

A relatively quiet weather is anticipated over the next few days as
surface high pressure remains in control over the north-central
Gulf. However, a few showers and storms cannot be ruled out,
particularly in the morning hours. Light to occasionally moderate
onshore winds and low seas will prevail through most of the week. An
increase in moisture, and hence, rain and storm chances, is expected
after Thursday as another disturbance develops along the
northeastern Gulf and moves westward across the Upper TX coast into
the weekend.

JM

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  95  76  96  75 /  20  20  10   0
Houston (IAH)  94  77  95  78 /  20  10   0   0
Galveston (GLS)  91  83  91  83 /  20  10  10  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

DISCUSSION...JM
AVIATION...Batiste
MARINE...JM